What is a domain MX record?
A domain MX record will redirect mail sent to joe@dept1.cornell.edu to a designated mailhost. The MX record is attached only to the domain name (dept1.cornell.edu). If a host exists with the same name as the domain, a “dangling” MX record is created which is not attached to any existing host. In either case, mail directed to the domain name is redirected to the mail exchange defined in the MX record. This does not effect mail sent directly to individual hosts in the domain. For example, if a domain MX exists for dept1.cornell.edu, with a mail exchange of mailhost.dept1.cornell.edu, then mail to joe@dept1.cornell.edu will be delivered to joe@mailhost.dept1.cornell.edu. What is a domain-wide MX record? A domain-wide MX record gets attached to every registered host in the domain. This function allows mail to be delivered to a central mailhost when incorrectly configured hosts may direct the reply mail back to the local machine. Some administrators discourage the use of incoming sendmail s
